Strain-specific TCR repertoire selection of IL-4-producing Thy-1 dull gamma delta thymocytes.

Thy-1 dull gamma delta thymocytes constitute an unusual subset of mature TCR gamma delta cells which share with NK T cells the expression of cell surface markers usually associated with activated or memory cells and the simultaneous production of high levels of IL-4 and IFN-gamma upon activation. In DBA / 2 mice, Thy-1 dull gamma delta thymocytes express a restricted repertoire of TCR that are composed of the V1 gene product mainly associated with V6.4 chains exhibiting very limited junctional sequence diversity.

Developmentally regulated and lineage-specific rearrangement of T cell receptor Valpha/delta gene segments.

To quantitate the frequency of Valpha/delta gene utilization by TCRgammadelta T cells we have generated a large panel of gammadelta T cell hybridomas and characterized their productive VDJ rearrangements. Using three novel mAb specific for the Vdelta5 chain and for several members of the Vdelta6 subfamily together with previously described Valpha- and Vdelta-specific mAb we have also quantitated the frequency of gammadelta and alphabeta cells expressing those Valpha/delta gene segments and located in different anatomical sites. We have also characterized the members of the Vdelta7/ADV10 subfamily expressed in C57BL/6 mice and analyzed the representation of individual ADV10 gene segments in alphabeta and gammadelta cells, as well as in precursor cells, in a situation in which TCR-dependent selection is negligible.

IL-4-producing gamma delta T cells that express a very restricted TCR repertoire are preferentially localized in liver and spleen.

IL-4-producing gamma delta thymocytes in normal mice belong to a distinct subset of gamma delta T cells characterized by low expression of Thy-1. This gamma delta thymocyte subset shares a number of phenotypic and functional properties with the NK T cell population. Thy-1dull gamma delta thymocytes in DBA/2 mice express a restricted repertoire of TCRs that are composed of the V gamma 1 gene product mainly associated with the V delta 6.

The homogeneity of the TCRdelta repertoire expressed by the Thy-1dull gammadelta T cell population is due to cellular selection.

Thy-1dull gammadelta T cells are an unusual subset of mature TCRgammadelta T cells characterized by their highly restricted TCR repertoire. In DBA/2 mice, they predominantly express the product of the Vgamma1 gene together with that of a member of the Vdelta6 subfamily (the Vdelta6.4 gene) and their junctional sequences show very little diversity.

A novel subset of adult gamma delta thymocytes that secretes a distinct pattern of cytokines and expresses a very restricted T cell receptor repertoire.

We have characterized the function, phenotype, ontogenic development, and T cell receptor (TCR) repertoire of a subpopulation of gamma delta thymocytes, initially defined by expressing low levels of Thy-1, that represents around 5% and 30% of total gamma delta thymocytes in adult C57BL/6 and DBA/2 mice, respectively. Activation of FACS-sorted Thy-1dull gamma delta thymocytes from DBA/2 mice with anti-gamma delta monoclonal antibodies in the presence of interleukin-2 (IL-2) results in the secretion of high levels of several cytokines, including interferon-gamma (IFN-gamma), IL-4, IL-10, and IL-3. In contrast, only IFN-gamma was detected in parallel cultures of Thy-1bright gamma delta thymocytes.